1) Field of the Invention
The present invention relates to a device for automatically adjusting a space between a pair of rolls forming a barrel; namely, a barrel width of a roll type straightener for a rolled section steel combined with a roll mill line.
2) Description of the Related Arts
When straightening a section steel, such as a H-shaped section steel, the width of a barrel must be adjusted to correspond to the web height of the section steel, and usually the barrel assembly is formed by a pair of rolls mounted on a main shaft with a space therebetween.
In the prior art, an adjustment of the space between the pair of rolls forming a barrel assembly is carried out by a device comprising a pair of displacement male and female screws mounted at a region of a main shaft between two rolls, through a sleeve, and a pair of tightening male and female screws mounted at one end of the sleeve. The roll distance, i.e., a barrel width, is adjusted by loosening the tightening screws, adjusting the displacement screws to form a required distance between both the rolls, and thereafter, fastening the tightening screws to fix the rolls in position on the main shaft. These operations for displacing the screws are manually conducted on the respective shafts, and are time-consuming and cumbersome.
To avoid the lowering of the machine efficiency due to the adjustment of the barrel width, many sets of barrel assemblies may be prepared, the respective assembly in each set having been preset to a certain width different from that in the other sets.
Accordingly, when a change of barrel width is needed, a suitable set of barrel assemblies is selected and mounted onto the main shaft, in place of the original set. This lessens the machine stop time for changing the barrel width, because the barrel assembly replacement can be performed in a shorter time than that needed for the width adjustment stated above. Nevertheless, another problem arisens in this system. Namely, the recent tendency toward "small lot-multivariation" has had an influence even in the marketing of section steel, which now needs a higher number of barrel sets corresponding to the increased width variations. Accordingly, all of the barrel sets of various widths can not be stored in a stockyard, due to a lack of space, and in a worst case, a barrel set suitable for a section steel to be straightened may not be easily available. In such a case, a barrel assembly having the required width must be immediately prepared while stopping the machine. This, of course, lowers the machine efficiency. Alternatively, a straightening operation may be carried out without changing the barrel assembly or adjusting the width thereof, to avoid the lowering of machine efficiency, but this lowers the quality of the product.
The multivariation tendency in the section steel market is accelerated by technical developments in the production of an H-shaped section steel. Namely, the conventional H-shaped section steel delivered from a roll mill includes a steel having a constant inner width H.sub.i, even though a flange thickness may be different, as shown in FIG. 5(a), and a barrel assembly with the same width can be used for straightening such group of section steel. Recently, another type of section steel having a constant outer width H.sub.0 with various flange thicknesses, which is produced mainly by a weld-assembly method, can be produced from the roll mill (see FIG. 5(b)), and also requires a straightening operation, but to straighten these new type section steels, a barrel assembly having various widths must be used.
Under the circumstances, the adjustment of barrel width on a machine is again necessary, while using the identical barrel assembly mounted thereon so that a section steel such as H-shaped steel having various width sizes can be treated thereby.
In this connection, a mechanism has been proposed in Japanese Examined Utility Model Publication koku) No. 64-6982 to lessen the abovesaid laborsome operation, in which a displacement of barrel roll on a main shaft during the width adjusting operation is carried out by a power cylinder having a pawl engageable with notches on the periphery of a displacement female screw. Although a part of the manual operation can be done by the power cylinder, the loosening and fastening of tightening screws still must be manually performed by the use of a specially designed spanner and a hammer. Further, this adjusting operation must be carried out while repeatedly checking the barrel width by hand. Accordingly, this device still requires a considerable operation time and labor to adjust the barrel width.